Rotatable finned heat transfer device

ABSTRACT

A heat transfer device includes first and second members mounted for continuous relative rotation in either of a clockwise or a counterclockwise direction while maintaining substantially equally sized gaps between a plurality of equally spaced concentric fins which are alternately disposed in overlapping relationship.

[451 Oct. 29, 1974 Elite Sttes Patet [191 Bimshas, 51', et al.

Kadenacy 60/3966 X Ahlen et al. 165/86 X Allen l65/86 X llll [54]ROTATABLE FINNED HEAT TRANSFER DEVICE [75] Inventors: John Bimshas, Jr.,Westwood;

Edward S. Hickey, Dover, both of Mass.

Primary Examiner-Albert W. Davis, Jr. Attorney, Agent, or Firm-R. S.Sciascia; Q. E. Hodges e h t m a CV. .lr em M imp D 5 h V. Shm 0 @Ma 8 ew hw a TrN E e n .W S S A l 3 U [22] Filed: May 22, 1972 ABSTRACT [21]Appl. No.: 255,848

A heat transfer device includes first and second members mounted forcontinuous relative rotation in either of a clockwise or acounterclockwise direction while maintaining substantially equally sizedgaps between a plurality of equally spaced concentric fins which arealternately disposed in overlapping relationship.

.LRUS M 8 8 1/31 N41 a6 7 72 l 8 2 7 F R 0 ,6 1 0 m 1 M N 6 67 1 I85 28// 6 ZfiW m 13 5 n. 6 n" 1 u" W Th e H .r. n a u w a L h C l0 S wum t unow HF 11 1] 2 00 5 55 l [l [56] References Cited UNITED STATES PATENTS1 Claim, 4 Drawing Figures 2,332,700 lO/l943Dickson.........................'...l65/86X t v.7 v

PATENTED BUT 2 9 I974 SHEET 1 (If 2 FIG. 2.

PAIENIEUHBI 29 I974 mama! FIG. 3.

FIG. 4.

ROTATABLE FINNED HEAT TRANSFER DEVICE BACKGROUND OF THE INVENTION 1.Field of the Invention DESCRIPTION OF THE PREFERRED EMBODIMENT Referringgenerally to FIGS. 1-3 and in particular to This invention relatesgenerally to heat exchange deit is shown that the rotatable finned heatvices and in particular to those having a movable heating or coolingsurface.

2. Description of the Prior Art Conventionally, when it was desired totransfer heat from a heat source to a relatively rotating heat sink, theonly practical means of transferring such heat was through compacthigh-speed blowers. Although such prior art devices are capable oftransferring heat, several disadvantages are connected with their use.For example, blowers consume power and may require special powersupplies. Also fan or blower devices can be noisy, induce vibration andgenerally have a relatively limited life. Furthermore, sincethermal-impedance will vary with changes in gas pressure, a blower speedcontroller must be used to limit the shifting of thermal graclients.

In applications such as the intergimbal assembly of inertial guidancestructures, there is a need for a novel heat transfer device to providea heat transfer path between the relatively rotating gimbals without theundesirable effects of blower devices.

SUMMARY OF THE INVENTION Accordingly, the present invention provides adevice to transfer heat from a heat source to a relatively rotating heatsink. This is accomplished substantially without the disadvantages ofthe fan and blower devices by providing a first member adapted forconnection to a heat source and a second member thermally coupled withthe first member and adapted for connection to a heat sink. Each of themembers have a plurality of equally spaced fins which are alternatelydisposed in overlapping relationship to form substantially equally sizedgaps therebetween. The first and second members are mounted forcontinuous relative rotation in either a clockwise or a counterclockwisedirection while maintaining the substantially equally sized gaps betweenthe fins.

OBJECTS OF THE INVENTION It is therefore an object of this invention toprovide a heat transfer path between a heat source and a relativelyrotating heat sink.

It is also an object of this invention to provide such a heat transferpath having substantially reduced variations in thermal impedance.

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a partial cut-awayisometric'view of the preferred embodiment of the invention;

FIG. 2 illustrates a partial cut-away isometric view of anotherembodiment;

FIG. 3 illustrates a partial cut-away isometric view of still anotherembodiment; and

FIG. 4 illustrates an isometric view of an alternat construction of theembodiment of FIG. 2.

fer device of a preferred embodiment of the present invention generallyincludes a first member 10 adapted for connection to a heat source (notshown). Member 10 includes a plurality of equally spaced concentric fins12.

A second member 14 is adapted for connection to a heat sink (not shown)and includes a plurality of equally spaced concentric fins 16. The finsl2 and 16 are alternately disposed in overlapping relationship to formsubstantially equally sized concentric gaps 18 therebetween.

The first and second members 10 and 14, including their respective finsl2 and 16, may be made preferably of aluminum although it is to beunderstood that any suitable material may be substituted. Grooves 20 offirst member 10 and grooves 22 of second member 14 may be preferablymachined by the electrical discharge method. The fin diameters arepreferably machined to a tolerance of i 0.001 inches each with aresulting radial gap 18 preferred to be of 0.005 to 0.007 inches betweenoverlapping fins 12 and 16.

Members 10 and 14 may be coaxially bearing mounted within theiroverlapping hubs or cores 24 and 26 respectively and the members may beretained in position by several retention means such as for example snaprings, threaded ring nuts, clamps or the like. In this manner, first andsecond members 10 and 14 respectively, are mounted for continuousrelative rotation in either a clockwise or a counterclockwise directionwhile maintaining the substantially equally sized gaps l8.

Specifically, the fins of first member 10 and second member 14 asillustrated in FIG. 1, form a plurality of equally spaced concentriccylinders.

In FIG. 2, fins or discs 12a and 16a of first and second members 10a and14a, respectively, form a plurality of equally spaced parallel discs.Similarly, in FIG. 3 fins or discs 12b of first member 10b and fins ordiscs 16b of second member 14b form a plurality of equally spacedparallel discs. Also, the device illustrated in FIGS. 2

and 3 have discs angularly disposed with the axis of rotation of themounted members. However, the discs 12a and 16a of FIG. 2 are rightangularly disposed whereas the discs 12b and 16b of FIG. 3 may bedismaximum permissible number of spacers and discs are alternatelydisposed to overlap and form equal gaps 18a therebetween. Similarly,members 14a and 10a may be retained mounted in rotating relationship bymeans of threaded ring nuts 36 and 38 or the like. Such a stacked typeconstruction would be substantially more economical to produce and wouldallow for greater radial misalignments. Any lack of stiffness of thediscs such as those shown in FIG. 2 could be increased by resultingconical shaped fins as illustrated in FIG. 3. The device of HG. 3 may beconstructed in a manner similar to that described for the device of FIG.2 however, appropriate parts would necessarily need to be tapered andformed to produce the desired resulting configuration as shown in FIG.3.

FIG. 4 illustrates, parts of the device in a detached relationship toshow another possible means of construction which could be used to forman embodiment similar to that of FIG. 2. First member 100 could bemachined to form a unit type construction having discs 120. Similarly,second member 140 could be machined in two halves to include fins 16c.Also grove 40 may be provided to accomodate bearing 30. The two halvesmay then be joined and retained as a unit by screws 42 or the like.

It is further anticipated that, if desired, first and second members and14 having concentric cylindrical fins l2 and 16 respectively, may bemounted for axial movement to vary the overlapping area of the fins thusproviding a variable impedance heat transfer device. Also, to furtherreduce thermal impedance, a substantially thermally efficient gas suchas helium or a liquid could be provided under pressure within the gaps.

The foregoing has described a novel heat transfer device to provide aheat transfer path between a relatively moving heat source and heat sinkwithout the undesirable effects of blower devices.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

l. A heat transfer device comprising:

a first member adapted for connection to a heat source and having aplurality of equally spaced parallel faced fins;

a second member adapted for connection to a heat sink and having aplurality of equally spaced parallel faced fins alternately disposed inoverlapping relationship with the first member fins to formsubstantially equally sized gaps therebetween;

the fins of the first and second members forming concentric hollowcylinders and being mounted for continuous relative rotation whilemaintaining the substantially equally sized gaps; and

means providing helium gas under pressure filling said gaps between saidfins.

1. A heat transfer device comprising: a first member adapted forconnection to a heat source and having a plurality of equally spacedparallel faced fins; a second member adapted for connection to a heatsink and having a plurality of equally spaced parallel faced finsalternately disposed in overlapping relationship with the first memberfins to form substantially equally sized gaps therebetween; the fins ofthe first and second members forming concentric hollow cylinders andbeing mounted for continuous relative rotation while maintaining thesubstantially equally sized gaps; and means providing helium gas underpressure filling said gaps between said fins.